Phased array modular high-frequency source

ABSTRACT

Embodiments described herein include a modular high-frequency emission source comprising a plurality of high-frequency emission modules and a phase controller. In an embodiment, each high-frequency emission module comprises an oscillator module, an amplification module, and an applicator. In an embodiment, each oscillator module comprises a voltage control circuit and a voltage controlled oscillator. In an embodiment, each amplification module is coupled to an oscillator module, in an embodiment, each applicator is coupled to an amplification module. In an embodiment, the phase controller is communicatively coupled to each oscillator module.

BACKGROUND

1) Field

Embodiments relate to the field of high-frequency emission sources and,in a particular embodiment, to a modular high-frequency emission sourcethat includes an array of high-frequency emission modules with eachhigh-frequency emission module comprising an oscillator module coupledto an amplification module and an applicator.

2) Description of Related Art

Use of high-frequency radiation systems, including for use in plasmaprocessing, are used extensively in the manufacture of many differenttechnologies, such as those in the semiconductor industry, displaytechnologies, microelectromechanical systems (MEMS), and the like.Currently, radio frequency (RF) radiation systems with a single antennaare most often used. However, in the case of plasmas generated with highfrequencies, including microwave frequencies, a plasma with higherplasma density and/or a plasma with a high concentration of excitedneutral species are formed. Unfortunately, high-frequency radiationsystems which are generated from a single antenna, for example thoseused to form plasmas, suffer their own drawbacks.

Typical high-frequency radiation systems, for example those to form amicrowave plasma, use a singular, large source of high-frequency ormicrowave radiation (e.g., a magnetron) and a transmission path forguiding the microwave radiation from the magnetron to the processingchamber. For example, in typical high power microwave applications inthe semiconductor industry the transmission path is a microwavewaveguide. Waveguides are used because outside of a waveguide designedto carry the specific frequency of the microwave source, the microwavepower attenuates rapidly with distance. Additional components, such astuners, couplers, mode transformers, and the like are also required totransmit the microwave radiation to the processing chamber. Thesecomponents limit the construction to large systems (i.e., at least aslarge as the sum of the waveguide and associated components), andseverely limit the design. As such, the geometry of the high-frequencyradiation field, which may be used to form a plasma, is constrainedsince the geometry of the high-frequency radiation field resembles theshape of waveguides.

Accordingly, it is difficult to match the geometry of a high-frequencyradiation field to the geometry of the substrate that is beingprocessed. In particular, it is difficult to create a high-frequencyradiation field at microwave frequencies, either to form a plasma or toexpose a substrate to radiation, where the process is uniformlyperformed on the whole area of the substrate (e.g., 200 mm, 300 mm orlarger diameter silicon wafers, glass substrates used in the displayindustry, or continuous substrates used in roll-to-roll manufacturing,or the like). Some microwave generated plasmas may use a slot lineantenna to allow the microwave energy to be spread over an extendedsurface. However, such systems are complicated, require specificgeometry, and are limited in the power density that can be coupled tothe plasma.

Furthermore, high-frequency radiation systems typically generateradiation fields and/or plasmas that are not highly uniform and/or arenot able to have a spatially tunable density. As the substrates that arebeing processed continue to increase in size, it becomes increasinglydifficult to account for edge effects. Additionally, the inability totune the radiation field and/or plasma limits the ability to modifyprocessing recipes to account for incoming substrate nonuniformity andadjust the radiation field density and/or the plasma density forprocessing systems in which a nonuniformity is required to compensatefor the design of the processing system (e.g., to accommodate thenonuniform radial velocity of the rotating wafers in some processingchambers).

SUMMARY

Embodiments described herein include a modular high-frequency emissionsource comprising a plurality of high-frequency emission modules and aphase controller. In an embodiment, each high-frequency emission modulecomprises an oscillator module, an amplification module, and anapplicator. In an embodiment, each oscillator module comprises a voltagecontrol circuit and a voltage controlled oscillator. In an embodiment,each amplification module is coupled to an oscillator module. In anembodiment, each applicator is coupled to an amplification module. In anembodiment, the phase controller is communicatively coupled to eachoscillator module.

Embodiments described herein include a modular high-frequency emissionsource. In an embodiment, the modular high-frequency emission sourcecomprises a plurality of high-frequency emission modules and a phasecontroller. In an embodiment, each high-frequency emission modulecomprises, an oscillator module, an amplification module, and anapplicator. In an embodiment the oscillator module comprises a voltagecontrol circuit and a voltage controlled oscillator, where an outputvoltage from the voltage control circuit drives oscillation in thevoltage controlled oscillator to generate an output high-frequencyelectromagnetic radiation. In an embodiment, the amplification module iscoupled to the oscillator module, and the amplification module amplifiesthe output high-frequency electromagnetic radiation from the voltagecontrolled oscillator. In an embodiment, the applicator is coupled tothe amplification module. In an embodiment, the phase controller iscommunicatively coupled to each of the oscillator modules. In anembodiment, the phase controller controls a phase relationship of theoutput high-frequency electromagnetic radiation generated by each of theoscillator modules.

Embodiments described herein include a processing tool that comprises aprocessing chamber and a modular high-frequency emission source. In anembodiment the modular high-frequency emission source comprises aplurality of high-frequency emission modules and a phase controller. Inan embodiment, each high-frequency emission module comprises anoscillator module, an amplification module, and an applicator. In anembodiment, each oscillator module comprises a voltage control circuitand a voltage controlled oscillator. In an embodiment, eachamplification module is coupled to an oscillator module In anembodiment, each applicator is coupled to an amplification module. In anembodiment, the applicator is positioned opposing a chuck in theprocessing chamber on which one or more substrates are processed. In anembodiment, the phase controller is communicatively coupled to eachoscillator module.

The above summary does not include an exhaustive list of allembodiments. It is contemplated that all systems and methods areincluded that can be practiced from all suitable combinations of thevarious embodiments summarized above, as well as those disclosed in theDetailed Description below and particularly pointed out in the claimsfiled with the application. Such combinations have particular advantagesnot specifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a processing tool that includes amodular high-frequency emission source, in accordance with anembodiment.

FIG. 2A is a schematic block diagram of a solid state high-frequencyemission module with feedback control, in accordance with an embodiment.

FIG. 2B is a schematic block diagram of a portion of the electronics ofa processing tool with a modular high-frequency emission source thatincludes oscillator modules that are electrically coupled to a phasecontroller and feedback control, in accordance with an embodiment.

FIG. 2C is a schematic block diagram of a portion of the electronics ofa processing tool with a modular high-frequency emission source thatincludes oscillator modules that are electrically coupled to a phasecontroller, in accordance with an embodiment.

FIG. 3 is cross-sectional illustration of an applicator that may be usedto couple microwave radiation to a processing chamber, in accordancewith an embodiment.

FIG. 4 is a cross-sectional illustration of an array of applicatorspositioned on a dielectric sheet that is part of the processing chamber,in accordance with an embodiment.

FIG. 5A is a plan view of an array of applicators that may be used tocouple microwave radiation to a processing chamber, in accordance withan embodiment.

FIG. 5B is a plan view of an array of applicators that may be used tocouple microwave radiation to a processing chamber, in accordance withan additional embodiment.

FIG. 5C is a plan view of an array of applicators and a plurality ofsensors for detecting conditions of a plasma, in accordance with anembodiment.

FIG. 5D is a plan view of an array of applicators that are formed in twozones of a multi-zone processing tool, in accordance with an embodiment.

FIG. 6 illustrates a block diagram of an exemplary computer system thatmay be used in conjunction with a modular microwave radiation source, inaccordance with an embodiment.

DETAILED DESCRIPTION

Devices in accordance with embodiments described herein include amodular high-frequency emission source that comprises an array ofhigh-frequency emission modules that are configured to function as aphased array. In the following description, numerous specific detailsare set forth in order to provide a thorough understanding ofembodiments. It will be apparent to one skilled in the art thatembodiments may be practiced without these specific details. In otherinstances, well-known aspects are not described in detail in order tonot unnecessarily obscure embodiments. Furthermore, it is to beunderstood that the various embodiments shown in the accompanyingdrawings are illustrative representations and are not necessarily drawnto scale.

Embodiments include a modular high-frequency emission source thatcomprises an array of high-frequency emission modules. As used herein,“high-frequency” electromagnetic radiation includes radio frequencyradiation, very-high-frequency radiation, ultra-high-frequencyradiation, and microwave radiation. “High-frequency” may refer tofrequencies between 0.1 MHz and 300 GHz. According to an embodiment,each high-frequency emission module comprises an oscillator module, anamplification module, and an applicator. In an embodiment, theoscillator module and the amplification module comprise electricalcomponents that are all solid state electronic components.

In an embodiment, the phase controller, the oscillator modules, and theamplification modules comprise electrical components that are all solidstate electronic components. The use of solid state electronics insteadof, for example a magnetron, allows for a significant reduction in thesize and the complexity of the a high-frequency radiation source.Particularly, the solid state components are much smaller than themagnetron hardware described above. Additionally, the use of solid statecomponents allows for the elimination of bulky waveguides needed totransmit the high-frequency radiation to the processing chamber.Instead, the high-frequency radiation may be transmitted with coaxialcabling. The elimination of waveguides also allows for the constructionof a large area modular high-frequency emission source where the size ofthe plasma formed is not limited by the size of waveguides. Instead, anarray of high-frequency emission modules may be constructed in a givenpattern that allows for the formation of a plasma that is arbitrarilylarge (and arbitrarily shaped) to match the shape of any substrate.Furthermore, the cross-sectional shape of the applicators may be chosenso that the array of applicators may be packed together as tightly aspossible (i.e., a closed-packed array).

The use of an array of high-frequency emission modules also providesgreater flexibility in the ability to locally change the radiation fieldand/or the plasma density by independently changing the power settingsof the amplification module for each high-frequency emission module.This allows for uniformity optimization during radiation field exposureand/or plasma processing, such as adjustments made for wafer edgeeffects, adjustments made for incoming wafer nonuniformity, and theability to adjust the radiation field exposure and/or plasma density forprocessing systems in which a nonuniformity is needed to compensate forthe design of the processing system (e.g., to accommodate the nonuniformradial velocity of the rotating wafers in some processing chambers).

Additional embodiments may also include one or more radiation fieldexposure and/or plasma monitoring sensors. Such embodiments provide away to measure the density of the plasma, or the electric fieldstrength, or any other plasma property or radiation field property,locally by each applicator, and to use that measurement as part of afeedback loop to control the power applied to each high-frequencyemission module. Accordingly, each high-frequency emission module mayhave independent feedback, or a subset of the high-frequency emissionmodules in the array may be grouped in zones of control where thefeedback loop controls the subset of high-frequency emission modules inthe zone.

In addition to the enhanced tuneability of the radiation field and/orthe plasma, the use of individual high-frequency emission modulesprovides a greater power density than are currently available inexisting radiation sources and/or plasma sources. For example,high-frequency emission modules may allow for a power density that isapproximately five or more times greater than typical RF plasmaprocessing systems. For example, typical power into a plasma enhancedchemical vapor deposition process is approximately 3,000 W, and providesa power density of approximately 4 W/cm² for a 300 mm diameter wafer. Incontrast, high-frequency emission modules according to embodiments mayuse a 300 W power amplifier with a 4 cm diameter applicator, to providea power density of approximately 24 W/cm² at an applicator packingdensity of approximately 1. At an applicator packing density of ⅓ andwith use of a 1000 W power amplifier, a power density of 27 W/cm² isprovided. At an applicator packing density of 1 and with use of a 1000 Wpower amplifier, a power density of 80 W/cm² is provided.

Usual approaches for making high-frequency radiation sources and/orplasmas (e.g., microwave plasmas) involve the use of a single oscillatormodule and a single electrode or applicator to couple the high-frequencyenergy to the substrate and/or, in the case of forming a plasma, to theprocess gas. However, using multiple electrode/applicator structureswith a single oscillator module that is split to power each of themultiple electrodes/applicators has drawbacks. Particularly, aninterference pattern will necessarily form because the electromagneticradiation generated by a single oscillator module results inelectromagnetic radiation emitted by each applicator to be at the samefrequency and at a fixed phase with each other. The interference patternproduces local maxima and minima that result in a nonuniform radiationfield and/or plasma.

Accordingly, embodiments include an array of high-frequency emissionmodules with each high-frequency emission module having its ownoscillator module. In order to provide control of the interferencepatterns generated by each oscillator module, the oscillator modules maybe communicatively coupled to a phase controller. In an embodiment, thephase controller may randomize the phase of electromagnetic radiationgenerated by each oscillator module in order to provide a uniformradiation field and/or plasma. For example, electromagnetic radiationgenerated by a first oscillator module may not interfere with theelectromagnetic radiation generated by a second oscillator modulebecause the first and second oscillator modules may not be at the samefrequency nor have a controlled phase difference between the first andsecond oscillator modules. In embodiments where a plasma is formed, theplasma will have improved uniformity since there is no interferencepattern. Similarly, when a plasma is not formed (e.g., microwave heatingor microwave curing), interference patterns are avoided and, in anembodiment more uniform heating or curing of the substrate is obtained.

In an additional embodiment, the phase controller may be used to providecontrolled interference of the electromagnetic radiation generated byeach of the oscillator modules. The frequency controller may allow forthe plurality of high-frequency emission modules to be operated as aphased array. For example, the phase controller may control the phaseand the frequency of the high-frequency electromagnetic radiationgenerated by each of the oscillator modules in order to provide furthercontrol of the shape of the radiation field and/or plasma by providingconstructive and destructive interference at desired locations in achamber. In an embodiment, phase control of the oscillator modules mayalso allow for a radiation field and/or plasma that may be dynamic(e.g., scanned, moved, modulated, etc.) within a chamber.

Referring now to FIG. 1, a cross-sectional illustration of a processingtool 100 is shown, according to an embodiment. In some embodiments, theprocessing tool 100 may be a processing tool suitable for any type ofprocessing operation that uses a radiation field and/or a plasma. Forexample, the processing tool 100 may be a processing tool used forplasma enhanced chemical vapor deposition (PECVD), plasma enhancedatomic layer deposition (PEALD), etch and selective removal processes,and plasma cleaning. While the embodiments described in detail hereinare directed to plasma processing tools, it is to be appreciated thatadditional embodiments may include a processing tool 100 that includesany tool that utilizes high-frequency electromagnetic radiation. Forexample, a processing tool 100 that utilizes high-frequencyelectromagnetic radiation without forming a plasma may includeindustrial heating, degassing, surface activation, and/or curingprocessing tools 100.

Generally, embodiments include a processing tool 100 that includes achamber 178. In processing tools 100, the chamber 178 may be a vacuumchamber. A vacuum chamber may include a pump (not shown) for removinggases from the chamber to provide the desired vacuum. Additionalembodiments may include a chamber 178 that includes one or more gaslines 170 for providing processing gasses into the chamber 178 andexhaust lines 172 for removing byproducts from the chamber 178. In anadditional embodiment, chamber 178 may be a pressure vessel, providingfor maintaining a pressure equal to or greater than one atmosphere ofpressure. While not shown, it is to be appreciated that the processingtool 100 may include a showerhead for evenly distributing the processinggases over a substrate 174. In some embodiments, the processing tool 100may optionally not include a chamber, (i.e., the processing tool 100 maybe a chamberless processing tool).

In an embodiment, the substrate 174 may be supported on a chuck 176. Forexample, the chuck 176 may be any suitable chuck, such as anelectrostatic chuck. The chuck may also include cooling lines and/or aheater to provide temperature control to the substrate 174 duringprocessing. Due to the modular configuration of the high-frequencyemission modules described herein, embodiments allow for the processingtool 100 to accommodate any sized substrate 174. For example, thesubstrate 174 may be a semiconductor wafer (e.g., 200 mm, 300 mm, 450mm, or larger). Alternative embodiments also include substrates 174other than semiconductor wafers. For example, embodiments may include aprocessing tool 100 configured for processing glass substrates, (e.g.,for display technologies).

According to an embodiment, the processing tool 100 includes a modularhigh-frequency emission source 104. The modular high-frequency emissionsource 104 may comprise an array of high-frequency emission modules 105.In an embodiment, each high-frequency emission module 105 may include anoscillator module 106, an amplification module 130, and an applicator142. In an embodiment, the oscillator module 106 and the amplificationmodule 130 may comprise electrical components that are solid stateelectrical components. In an embodiment, each of the plurality ofoscillator modules 106 may be communicatively coupled to differentamplification modules 130. In some embodiments, there may be a 1:1 ratiobetween oscillator modules 106 and amplification modules 130. Forexample, each oscillator module 106 may be electrically coupled to asingle amplification module 130.

In an embodiment, each oscillator module 106 generates electromagneticradiation that is transmitted to the amplification module 130. Afterprocessing by the amplification module 130, the electromagneticradiation is transmitted to the applicator 142. According to anembodiment, an array 140 of applicators 142 are coupled to the chamber178 and each emit the electromagnetic radiation into the chamber 178. Insome embodiments, the applicators 142 couple the electromagneticradiation to the processing gasses in the chamber 178 to produce aplasma.

Referring now to FIG. 2A, a schematic block diagram of the electronicsin a high-frequency emission module 105 in the modular high-frequencyemission source 104 is shown, according to an embodiment. In anembodiment, each oscillator module 106 includes a voltage controlcircuit 210 for providing an input voltage to a voltage controlledoscillator 220 in order to produce high-frequency electromagneticradiation at a desired frequency. Embodiments may include an inputvoltage between approximately 1V and 10V DC. The voltage controlledoscillator 220 is an electronic oscillator whose oscillation frequencyis controlled by the input voltage. According to an embodiment, theinput voltage from the voltage control circuit 210 results in thevoltage controlled oscillator 220 oscillating at a desired frequency. Inan embodiment, the high-frequency electromagnetic radiation may have afrequency between approximately 0.1 MHz and 30 MHz. In an embodiment,the high-frequency electromagnetic radiation may have a frequencybetween approximately 30 MHz and 300 MHz. In an embodiment, thehigh-frequency electromagnetic radiation may have a frequency betweenapproximately 300 MHz and 1 GHz. In an embodiment, the high-frequencyelectromagnetic radiation may have a frequency between approximately 1GHz and 300 GHz. In an embodiment, the one or more of the plurality ofoscillator modules 106 may emit electromagnetic radiation at differentfrequencies.

According to an embodiment, the electromagnetic radiation is transmittedfrom the voltage controlled oscillator 120 to the amplification module130. The amplification module 130 may include a driver/pre-amplifier234, and a main power amplifier 236 that are each coupled to a powersupply 239. According to an embodiment, the amplification module 130 mayoperate in a pulse mode. For example, the amplification module 130 mayhave a duty cycle between 1% and 99%. In a more particular embodiment,the amplification module 130 may have a duty cycle between approximately15% and 50%.

In an embodiment, the electromagnetic radiation may be transmitted tothe applicator 142 after being processed by the amplification module130. However, part of the power transmitted to the applicator 142 may bereflected back due to the mismatch in the output impedance. Accordingly,some embodiments include a detector module 281 that allows for the levelof forward power 283 and reflected power 282 to be sensed and fed backto the control circuit module 221. It is to be appreciated that thedetector module 281 may be located at one or more different locations inthe system. In an embodiment, the control circuit module 221 interpretsthe reflected power 282 and the forward power 283, and determines thelevel for the control signal 285 that is communicatively coupled to theoscillator module 106, and level for the control signal 286 that iscommunicatively coupled to the amplifier module 130. In an embodiment,control signal 285 adjusts the oscillator module 106 to optimize thehigh-frequency of the radiation coupled to the amplification module 130.In an embodiment, control signal 286 adjusts the amplifier module 130 tooptimize the output power coupled to applicator 142.

In an embodiment, the feedback control of the oscillator module 106 andthe amplification module 130 may allow for the level of the reflectedpower to be less than approximately 5% of the forward power. In someembodiments, the feedback control of the oscillator module 106 and theamplification module 130 may allow for the level of the reflected powerto be less than approximately 2% of the forward power. Accordingly,embodiments allow for an increased percentage of the forward power to becoupled into the processing chamber 178, and increases the availablepower coupled to the plasma. Furthermore, impedance tuning using afeedback control is superior to impedance tuning in typical slot-plateantennas. In slot-plate antennas, the impedance tuning involves movingtwo dielectric slugs formed in the applicator. This involves mechanicalmotion of two separate components in the applicator, which increases thecomplexity of the applicator. Furthermore, the mechanical motion may notbe as precise as the change in frequency that may be provided by avoltage controlled oscillator 220.

Referring now to FIG. 2B, a schematic of a portion of the solid stateelectronics of a modular high-frequency emission source 104 with anarray of high-frequency emission modules 105 is shown, in accordancewith an embodiment. In the illustrated embodiment, each high-frequencyemission module 105 includes an oscillator module 106 that iscommunicatively coupled to a different amplification module 130. Each ofthe amplification modules 130 may be coupled to different applicators142. In an embodiment, a control circuit 221 may be communicativelycoupled to the oscillator module 106 and the amplification module 130.

In an embodiment, each of the plurality of oscillator modules 106 arecommunicatively coupled to a phase controller 295. In an embodiment, thephase controller 295 may be used to control a phase relationship andfrequency of electromagnetic radiation generated by each of theoscillator modules 106. For example, the phase controller 295 mayinclude a processor that generates a signal that is transmitted to eachoscillator module 106. The signal may initiate the oscillator modules106 at different times in order to generate different phases.

In such an embodiment, the phase controller 295 allows for theapplicators 142 of each high-frequency emission modules 105 to beoperated as part of a phased array. A phased array allows for theelectromagnetic radiation emitted by each of the applicators 142 to addtogether (i.e., constructive interference) to increase the radiation ina desired location of the chamber, while cancelling (i.e., destructiveinterference) to suppress radiation in undesired locations of thechamber 178. The spatial relationship of the applicators 142 and thefrequency of the electromagnetic radiation generated by the oscillatormodules 106 may be inputs used by the phase controller 295 to determinethe phase relationship of the electromagnetic radiation needed to form adesired electromagnetic radiation pattern in the processing chamber 178.

In an embodiment, the phase controller 295 may be operated to provide astatic electromagnetic radiation pattern in the chamber 178. Forexample, a static electromagnetic radiation pattern may refer to arelatively unchanging pattern of constructive and destructiveinterference in the chamber 178. In an embodiment, the phase controller295 may be operated to provide a dynamic electromagnetic radiationpattern in the chamber 178. For example, a dynamic electromagneticradiation pattern may refer to a pattern where the local maxima and/orminima are moved throughout the volume of the chamber 178. Such anembodiment may be beneficial when used in processing tools that includesubstrates that are moved through different processing zones.

In the illustrated embodiment, each of the oscillator modules 106 andthe amplification modules 130 are formed on a single board 290, such asa printed circuit board (PCB). However, it is to be appreciated that theoscillator modules 106 and the amplification module 130 may be formed ontwo or more different boards 290. In the illustrated embodiment fourhigh-frequency emission modules 105 are shown. However, it is to beappreciated that the modular high-frequency emission source 104 mayinclude two or more high-frequency emission modules 105. For example themodular high-frequency emission source 104 may include 2 or morehigh-frequency emission modules, 5 or more high-frequency emissionmodules, 10 or more high-frequency emission modules, or 25 or morehigh-frequency emission modules.

In accordance with an additional embodiment, a single oscillator module106 may be used to form a phased array. In such an embodiment, thehigh-frequency electromagnetic radiation from the single oscillator 106may be split and transmitted to each high-frequency emission module 105.The each high-frequency emission module 105 may include a phase shifteror other signal modifier that may modify the high-frequencyelectromagnetic radiation from the single oscillator 106. Accordingly,the high-frequency electromagnetic radiation generated by eachhigh-frequency emission module 105 may be the same, and thehigh-frequency electromagnetic radiation generated by the high frequencyemission modules 105 may have a controlled phase relationship.

Referring now to FIG. 2C, a schematic of a portion of the solid stateelectronics of a modular high-frequency emission source 104 with anarray of high-frequency emission modules 105 is shown, in accordancewith an embodiment. FIG. 2C is substantially similar to the systemillustrated in FIG. 2B, with the exception that the control circuit isomitted. Particularly, in some embodiments the feedback control providedby a detector and the control circuit may not be needed.

Referring now to FIG. 3, a cut-away illustration of an applicator 142 isshown, according to an embodiment. In an embodiment, the electromagneticradiation is transmitted to an applicator 142 by a coaxial cable 351that couples to a monopole 357 that extends axially through theapplicator 142. In an embodiment where the electromagnetic radiation ismicrowave radiation, the monopole 357 may also extend into a channel 358formed into a center of a dielectric resonant cavity 353. The dielectricresonant cavity 353 may be a dielectric material, such as quartz,aluminum oxide, titanium oxide, or the like. Additional embodiments mayalso include a resonant cavity 353 that does not include a material(i.e., the dielectric resonant cavity 353 may be air or a vacuum).According to an embodiment, the dielectric resonator is dimensioned sothat the dielectric resonator supports resonance of the microwaveradiation. Generally, the size of the dielectric resonant cavity 353 isdependent on the dielectric constant of the material used to form thedielectric resonant cavity 353 and the frequency of the microwaveradiation. For example, materials with higher dielectric constants wouldallow for smaller resonant cavities 353 to be formed. In an embodimentwhere the dielectric resonant cavity 353 includes a circularcross-section, the diameter of the dielectric resonant cavity 353 may bebetween approximately 1 cm and 15 cm. In an embodiment, thecross-section of the dielectric resonant cavity 353 along a planeperpendicular to the monopole 357 may be any shape, so long as thedielectric resonant cavity 353 is dimensioned to support resonance. Inthe illustrated embodiment, the cross-section along a planeperpendicular to the monopole 357 is circular, though other shapes mayalso be used, such as polygons (e.g., triangles, rectangles, etc.),symmetrical polygons (e.g., squares, pentagons, hexagons, etc.),ellipses, or the like).

In an embodiment, the cross-section of the dielectric resonant cavity353 may not be the same at all planes perpendicular to the monopole 357.For example, the cross-section of a bottom extension proximate to theopen end of the applicator housing 355 is wider than the cross-sectionof the dielectric resonant cavity proximate to the channel 358. Inaddition to having cross-sections of different dimensions, thedielectric resonant cavity 353 may have cross-sections with differentshapes. For example, the portion of the dielectric resonant cavity 353proximate to the channel 358 may have a circular shaped cross-section,whereas the portion of the dielectric resonant cavity 353 proximate tothe open end of the applicator housing 355 may be a symmetrical polygonshape (e.g., pentagon, hexagon, etc.). However, it is to be appreciatedthat embodiments may also include a dielectric resonant cavity 353 thathas a uniform cross-section at all planes perpendicular to the monopole357.

According to an embodiment, the applicator 353 may also include animpedance tuning backshort 356. The backshort 356 may be a displaceableenclosure that slides over an outer surface of the applicator housing355. When adjustments to the impedance need to be made, an actuator (notshown) may slide the backshort 356 along the outer surface of theapplicator housing 355 to change a distance D between a surface of thebackshort 356 and a top surface of the dielectric resonant cavity 353.As such, embodiments provide more than one way to adjust the impedancein the system. According to an embodiment, an impedance tuning backshort356 may be used in conjunction with the feedback process described aboveto account for impedance mismatches. Alternatively, the feedback processor an impedance tuning backshort 356 may be used by themselves to adjustfor impedance mismatches.

According to an embodiment, the applicator 142 functions as a dielectricantenna that directly couples the microwave electromagnetic field intothe processing chamber 178. The particular axial arrangement of themonopole 357 entering the dielectric resonant cavity 353 may produce anTM01δ mode excitation. However different modes of excitation may bepossible with different applicator arrangements. For example, while anaxial arrangement is illustrated in FIG. 3, it is to be appreciated thatthe monopole 357 may enter the dielectric resonant cavity 353 from otherorientations. In one such embodiment, the monopole 357 may enter thedielectric resonant cavity 353 laterally, (i.e., through a sidewall ofthe dielectric resonant cavity 353).

It is to be appreciated that the applicator 142 illustrated in FIG. 3 isexemplary in nature, and embodiments are not limited to the designdescribed. For example, the applicator 142 in FIG. 3 is particularlysuitable for emitting microwave radiation. However, embodiments mayinclude any applicator design that is configured to emit anyhigh-frequency electromagnetic radiation.

Referring now to FIG. 4, an illustration of a portion of a processingtool 100 with an array 140 of applicators 142 coupled to the chamber 178is shown, according to an embodiment. In the illustrated embodiment, thehigh-frequency electromagnetic radiation from the applicators 142 iscoupled into the chamber 178 by being positioned proximate to adielectric plate 450. The proximity of the applicators 142 to thedielectric plate 450 allows for the high-frequency radiation resonatingin the dielectric resonant cavity 353 (not shown in FIG. 4) to couplewith the dielectric plate 450, which may then couple with processinggasses in the chamber to generate a plasma. In some embodiments where aplasma is not induced, the high-frequency radiation is coupled into thechamber volume to generate a radiation field. In one embodiment, thedielectric resonant cavity 353 may be in direct contact with thedielectric plate 350. In an additional embodiment, the dielectricresonant cavity 353 may be spaced away from a surface of the dielectricplate 450, so long as the microwave radiation can still be transferredto the dielectric plate 450. In additional embodiments, the applicators142 may be set into cavities in the dielectric plate 450. In yet anotherembodiment, the applicators 142 may pass through the dielectric plate450, so that the dielectric resonant cavities 353 are exposed to theinterior of the chamber 178.

In an embodiment, the applicators 142 may include any antenna designthat is configured to emit any frequency of the high-frequencyelectromagnetic radiation. In an embodiment, the array 140 ofapplicators may include more than one applicator 142 design. Forexample, the array 140 of applicators 142 may include a first applicatorfor emitting a first high-frequency radiation and a second applicatorfor emitting a second high-frequency radiation that is different thanthe first high-frequency radiation.

According to an embodiment, the array 140 of applicators 142 may beremovable from the dielectric plate 450 (e.g., for maintenance, torearrange the array of applicators to accommodate a substrate withdifferent dimensions, or for any other reason) without needing to removethe dielectric plate 350 from the chamber 178. Accordingly, theapplicators 142 may be removed from the processing tool 100 withoutneeding to release a vacuum in the chamber 178. According to anadditional embodiment, the dielectric plate 450 may also function as agas injection plate or a showerhead.

As noted above, an array of applicators 140 may be arranged so that theyprovide coverage of an arbitrarily shaped substrate 174. FIG. 5A is aplan view illustration of an array 140 of applicators 142 that arearranged in a pattern that matches a circular substrate 174. By forminga plurality of applicators 142 in a pattern that roughly matches theshape of the substrate 174, the radiation field and/or plasma becomestunable over the entire surface of the substrate 174. For example, eachof the applicators 142 may be controlled so that a plasma with a uniformplasma density across the entire surface of the substrate 174 is formedand/or a uniform radiation field across the entire surface of thesubstrate 174 is formed. Alternatively, one or more of the applicators142 may be independently controlled to provide plasma densities that arevariable across the surface of the substrate 174. As such, incomingnonuniformity present on the substrate may be corrected. For example,the applicators 142 proximate to an outer perimeter of the substrate 174may be controlled to have a different power density than applicatorsproximate to the center of the substrate 174. Furthermore, it is to beappreciated that the use of high-frequency emission modules 105 that arecommunicatively coupled to a phase controller (as described above) mayfunction as a phased array and allow for controlled interference toprovide a radiation field and/or plasma with static maxima and minima atdesired locations, a radiation field and/or plasma with dynamic maximaand minima, and/or a uniform radiation field and/or plasma.

In FIG. 5A, the applicators 142 in the array 140 are packed together ina series of concentric rings that extend out from the center of thesubstrate 174. However, embodiments are not limited to suchconfigurations, and any suitable spacing and/or pattern may be useddepending on the needs of the processing tool 100. Furthermore,embodiments allow for applicators 142 with any symmetricalcross-section, as described above. Accordingly, the cross-sectionalshape chosen for the applicator may be chosen to provide enhancedpacking efficiency.

Referring now to FIG. 5B, a plan view of an array 140 of applicators 142with a non-circular cross-section is shown, according to an embodiment.The illustrated embodiment includes applicators 142 that have hexagonalcross-sections. The use of such an applicator may allow for improvedpacking efficiency because the perimeter of each applicator 142 may matenearly perfectly with neighboring applicators 142. Accordingly, theuniformity of the plasma may be enhanced even further since the spacingbetween each of the applicators 142 may be minimized. While FIG. 5Billustrates neighboring applicators 142 sharing sidewall surfaces, it isto be appreciated that embodiments may also include non-circularsymmetrically shaped applicators that include spacing betweenneighboring applicators 142.

Referring now to FIG. 5C, an additional plan-view illustration of anarray 140 of applicators 142 is shown according to an embodiment. Thearray 140 in FIG. 5C is substantially similar to the array 140 describedabove with respect to FIG. 5A, except that a plurality of sensors 590are also included. The plurality of sensors provides improved processmonitoring capabilities that may be used to provide additional feedbackcontrol of each of the modular microwave sources 105. In an embodiment,the sensors 590 may include one or more different sensor types 590, suchas plasma density sensors, plasma emission sensors, radiation fielddensity sensors, radiation emission sensors, or the like. Positioningthe sensors across the surface of the substrate 174 allows for theradiation field and/or plasma properties at given locations of theprocessing chamber 100 to be monitored.

According to an embodiment, every applicator 142 may be paired with adifferent sensor 590. In such embodiments, the output from each sensor590 may be used to provide feedback control for the respectiveapplicator 142 to which the sensor 590 has been paired. Additionalembodiments may include pairing each sensor 590 with a plurality ofapplicators 142. For example, each sensor 590 may provide feedbackcontrol for multiple applicators 142 to which the sensor 590 isproximately located. In yet another embodiment, feedback from theplurality of sensors 590 may be used as a part of a multi-inputmulti-output (MIMO) control system. In such an embodiment, eachapplicator 142 may be adjusted based on feedback from multiple sensors590. For example, a first sensor 590 that is a direct neighbor to afirst applicator 142 may be weighted to provide a control effort to thefirst applicator 142 that is greater than the control effort exerted onthe first applicator 142 by a second sensor 590 that is located furtherfrom the first applicator 142 than the first sensor 590.

Referring now to FIG. 5D, an additional plan-view illustration of anarray 140 of applicators 142 positioned in a multi-zone processing tool100 is shown, according to an embodiment. In an embodiment, themulti-zone processing tool 100 may include any number of zones. Forexample, the illustrated embodiment includes zones 575 ₁-575 _(n). Eachzone 575 may be configured to perform different processing operations onsubstrates 174 that are rotated through the different zones 575. Asillustrated, a first array 1402 is positioned in zone 5752 and a secondarray 140 _(n) is positioned in zone 575 _(n). However, embodiments mayinclude multi-zone processing tools 100 with an array 140 of applicators142 in one or more of the different zones 575, depending on the needs ofthe device. The spatially tunable density of the plasma and/or radiationfield provided by embodiments allows for the accommodation of nonuniformradial velocity of the rotating substrates 174 as they pass through thedifferent zones 475.

Referring now to FIG. 6, a block diagram of an exemplary computer system660 of a processing tool 100 is illustrated in accordance with anembodiment. In an embodiment, computer system 660 is coupled to andcontrols processing in the processing tool 100. Computer system 660 maybe connected (e.g., networked) to other machines in a Local Area Network(LAN), an intranet, an extranet, or the Internet. Computer system 660may operate in the capacity of a server or a client machine in aclient-server network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. Computer system 660may be a personal computer (PC), a tablet PC, a set-top box (STB), aPersonal Digital Assistant (PDA), a cellular telephone, a web appliance,a server, a network router, switch or bridge, or any machine capable ofexecuting a set of instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated for computer system 660, the term “machine” shallalso be taken to include any collection of machines (e.g., computers)that individually or jointly execute a set (or multiple sets) ofinstructions to perform any one or more of the methodologies describedherein.

Computer system 660 may include a computer program product, or software622, having a non-transitory machine-readable medium having storedthereon instructions, which may be used to program computer system 660(or other electronic devices) to perform a process according toembodiments. A machine-readable medium includes any mechanism forstoring or transmitting information in a form readable by a machine(e.g., a computer). For example, a machine-readable (e.g.,computer-readable) medium includes a machine (e.g., a computer) readablestorage medium (e.g., read only memory (“ROM”), random access memory(“RAM”), magnetic disk storage media, optical storage media, flashmemory devices, etc.), a machine (e.g., computer) readable transmissionmedium (electrical, optical, acoustical or other form of propagatedsignals (e.g., infrared signals, digital signals, etc.)), etc.

In an embodiment, computer system 660 includes a system processor 602, amain memory 604 (e.g., read-only memory (ROM), flash memory, dynamicrandom access memory (DRAM) such as synchronous DRAM (SDRAM) or RambusDRAM (RDRAM), etc.), a static memory 606 (e.g., flash memory, staticrandom access memory (SRAM), etc.), and a secondary memory 618 (e.g., adata storage device), which communicate with each other via a bus 630.

System processor 602 represents one or more general-purpose processingdevices such as a microsystem processor, central processing unit, or thelike. More particularly, the system processor may be a complexinstruction set computing (CISC) microsystem processor, reducedinstruction set computing (RISC) microsystem processor, very longinstruction word (VLIW) microsystem processor, a system processorimplementing other instruction sets, or system processors implementing acombination of instruction sets. System processor 602 may also be one ormore special-purpose processing devices such as an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA), adigital signal system processor (DSP), network system processor, or thelike. System processor 602 is configured to execute the processing logic626 for performing the operations described herein.

The computer system 660 may further include a system network interfacedevice 608 for communicating with other devices or machines. Thecomputer system 660 may also include a video display unit 610 (e.g., aliquid crystal display (LCD), a light emitting diode display (LED), or acathode ray tube (CRT)), an alphanumeric input device 612 (e.g., akeyboard), a cursor control device 614 (e.g., a mouse), and a signalgeneration device 616 (e.g., a speaker).

The secondary memory 618 may include a machine-accessible storage medium631 (or more specifically a computer-readable storage medium) on whichis stored one or more sets of instructions (e.g., software 622)embodying any one or more of the methodologies or functions describedherein. The software 622 may also reside, completely or at leastpartially, within the main memory 604 and/or within the system processor602 during execution thereof by the computer system 660, the main memory604 and the system processor 602 also constituting machine-readablestorage media. The software 622 may further be transmitted or receivedover a network 620 via the system network interface device 608.

While the machine-accessible storage medium 631 is shown in an exemplaryembodiment to be a single medium, the term “machine-readable storagemedium” should be taken to include a single medium or multiple media(e.g., a centralized or distributed database, and/or associated cachesand servers) that store the one or more sets of instructions. The term“machine-readable storage medium” shall also be taken to include anymedium that is capable of storing or encoding a set of instructions forexecution by the machine and that cause the machine to perform any oneor more of the methodologies. The term “machine-readable storage medium”shall accordingly be taken to include, but not be limited to,solid-state memories, and optical and magnetic media.

In the foregoing specification, specific exemplary embodiments have beendescribed. It will be evident that various modifications may be madethereto without departing from the scope of the following claims. Thespecification and drawings are, accordingly, to be regarded in anillustrative sense rather than a restrictive sense.

1. A modular high-frequency emission source, comprising: a plurality ofhigh-frequency emission modules, wherein each high-frequency emissionmodule comprises: an oscillator module, wherein each oscillator modulecomprises: a voltage control circuit; and a voltage controlledoscillator; an amplification module, wherein the amplification module iscoupled the oscillator module; an applicator, wherein the applicator iscoupled to the amplification module; and a phase controllercommunicatively coupled to each oscillator module.
 2. The modularhigh-frequency emission source of claim 1, wherein the applicator ofeach high-frequency emission module is part of a phased array.
 3. Themodular high-frequency emission source of claim 2, wherein the phasecontroller controls a phase relationship of electromagnetic radiationgenerated by the oscillator modules in order to form an electromagneticradiation pattern emitted by the phased array.
 4. The modularhigh-frequency emission source of claim 3, wherein the electromagneticradiation pattern is a static pattern.
 5. The modular high-frequencyemission source of claim 3, wherein the electromagnetic radiationpattern is a dynamic pattern.
 6. The modular high-frequency emissionsource of claim 1, wherein the high-frequency is a microwave frequency.7. The modular high-frequency emission source of claim 1, wherein thehigh-frequency is 0.1 MHz to 300 GHz.
 8. A modular high-frequencyemission source, comprising: a plurality of high-frequency emissionmodules, wherein each high-frequency emission module comprises: anoscillator module, wherein the oscillator module comprises: a voltagecontrol circuit; and a voltage controlled oscillator, wherein an outputvoltage from the voltage control circuit drives oscillation in thevoltage controlled oscillator to generate an output high-frequencyelectromagnetic radiation; an amplification module, wherein theamplification module is coupled to the oscillator module, wherein theamplification module amplifies the output high-frequency electromagneticradiation from the voltage controlled oscillator; an applicator, whereinthe applicator is coupled to the amplification module; and a phasecontroller communicatively coupled to each of the oscillator modules,wherein the phase controller controls a phase relationship of the outputhigh-frequency electromagnetic radiation generated by each of theoscillator modules.
 9. The modular high-frequency emission source ofclaim 8, wherein the output high-frequency electromagnetic radiationexcites a plasma.
 10. The modular high-frequency emission source ofclaim 8, wherein the applicator of each high-frequency emission moduleis part of a phased array.
 11. The modular high-frequency emissionsource of claim 10, wherein the phase controller generates anelectromagnetic pattern emitted by the phased array.
 12. The modularhigh-frequency emission source of claim 11, wherein the electromagneticradiation pattern is a static pattern.
 13. The modular high-frequencyemission source of claim 11, wherein the electromagnetic radiationpattern is a dynamic pattern.
 14. The modular high-frequency emissionsource of claim 8, wherein the high-frequency is a microwave frequency.15. A processing tool, comprising: a processing chamber; and a modularhigh-frequency emission source, comprising: a plurality ofhigh-frequency emission modules, wherein each high-frequency emissionmodule comprises: an oscillator module, wherein each oscillator modulecomprises: a voltage control circuit; and a voltage controlledoscillator; an amplification module, wherein the amplification module iscoupled to the oscillator module; and an applicator, wherein theapplicator is coupled to the amplification module, and wherein theapplicator is positioned opposing a chuck in the processing chamber onwhich one or more substrates are processed; and a phase controllercommunicatively coupled to each oscillator module.
 16. The processingtool of claim 15, wherein the applicator of each high-frequency emissionmodule is part of a phased array.
 17. The processing tool of claim 16,wherein the phase controller controls a phase relationship ofelectromagnetic radiation generated by the oscillator modules in orderto form an electromagnetic radiation pattern emitted by the phasedarray.
 18. The processing tool of claim 17, wherein the electromagneticradiation excites a plasma.
 19. The processing tool of claim 17, whereinthe electromagnetic radiation pattern is a dynamic pattern.
 20. Theprocessing tool of claim 15, wherein the high-frequency is a microwavefrequency.